Pa Nature Journeys: State partners with feds for eagle count

The small group talked animatedly in the small parking area near the Susquehanna River, discussing strategy for the day. An uncommon foggy winter morning had thrown a curveball for at least one team for the Mid-Winter Bald Eagle count. Volunteers often brave wind and cold, as well as nearly frozen fingers. Today they faced fog and were concerned about the success of their task.

The bald eagle count is part of a nationwide survey conducted by the Army Corps of Engineers, coordinated in Pennsylvania by Patricia Barber, endangered bird biologist for Pennsylvania Game Commission (PGC).

For 24 years, Charlotte (Chotty) Sprenkle, watershed coordinator for Chester County Conservation District, has led the volunteer team that covers the eastern shoreline of the Susquehanna River from Peach Bottom Nuclear Power Plant, upriver to Safe Harbor Dam. The team ranges from three to seven members: naturalists Jill Showalter, Lancaster County; and Joy Howell, York County; are the team’s mainstays with more than10years each. This survey was the fourth year for this reporter. Sprenkle has several times conducted the survey alone.

An unusual aspect of this year’s Susquehanna River segment of the eagle survey was the accompaniment of Hal Korber, prize winning wildlife videographer for PGC. Korber’s natural history videos on Pennsylvania whitetail deer, elk and black bears have been universally well received.

Advertisement

The bald eagle video being filmed by Korber is just part of PGC’s yearlong 35th anniversary celebration of the state’s wildly successful bald eagle recovery program. This column will deal more fully with that at a later date. The short version is that in 1983 there were just three pairs of nesting bald eagles in Pennsylvania, and last spring there were 237 pairs, according to Barber.

“We have 107 routes across the state that teams survey each winter,” said Barber. Sprenkle’s route usually has about eight stops, or survey locations, where she and her team spend 30-minutes scanning the sky, trees, power towers and any areas that might have eagles visible. Fog notwithstanding, all but one spot had adequate visibility for the team’s viewing. Revisiting the fogged-in location at the end of the day provided the visibility for the survey team to be spot several eagles.

With or without binoculars, the team’s eyesight is stellar, and it is a rare eagle within the count area that goes uncounted. This year’s lower Susquehanna River count totaled 10 bald eagles - seven adults and three immature birds. Adult bald eagles are 5 years old and have fully white heads and tails. Immature birds are very dark, have some white on their undersides, but lack white heads and tails. With their 6½- to 7½-foot wingspan, white heads and tails, adult bald eagles are hard to miss, and impossible to misidentify.

“During last year’s Mid-Winter Eagle Count,” said Barber, “48 Pennsylvania volunteers counted 59 bald eagles.” She said that because there was little ice on state rivers and lakes during last year’s count, eagles were able to spread out over large areas, making them more difficult to locate and count. Barber explained that, “During years with much of the water frozen and closed-off to feeding eagles, the large, fish-eating birds congregate at smaller areas of open water to feed, and are easier to find and count.”

Asked the origins of the bald eagles living along the lower Susquehanna, Barber related that the majority of the eagles are local birds, many being offspring of the Canadian eagles introduced several decades ago and released north of Harrisburg. Others, she said, are progeny of those birds. (Every five years a new age class of bald eagles can breed.) Finally, Barber said some birds from the Chesapeake Bay move upriver searching for open territories to inhabit. “Not all eagles migrate long distances north to south in autumn like many other birds we’re familiar with,” said Barber, “many eagles migrate, or actually just move, regionally, and may move either north to south or south to north.” She explained further that some bald eagles from the upper Chesapeake move north for periods of time, while southern bald eagles sometimes actually migrate north fairly long distances.

The occasionally jumbled method of eagle migration and/or movement is just one more reason for the annual mid-winter eagle survey. We will learn more about our state’s eagles as the year progresses.

John McGonigle lives in the West Chester area. He writes for numerous nature magazines.